function wz(url,data,callback) {
  let xmlHttp= new XMLHttpRequest()
  xmlHttp.open('POST',url)
  xmlHttp.setRequestHeader('content-type','application/json;charset=utf-8')
  xmlHttp.send(JSON.stringify(data))
  xmlHttp.onreadystatechange=function () {
    if (xmlHttp.readyState  ==  4 &&  xmlHttp.status==200){
      let result=JSON.parse(xmlHttp.responseText)
      if(result.code !==200){
        alert(result.message)
        return
      }
      callback(result)
    }
  }
}

function getQueryVariable(variable)
{
  var query = window.location.search.substring(1);
  var vars = query.split("&");
  for (var i=0;i<vars.length;i++) {
    var pair = vars[i].split("=");
    if(pair[0] == variable){return pair[1];}
  }
  return(false);
}